Met Office upgrades Storm Callum warning to Amber as 80mph winds and three days of rain to batter Britain

"Danger to life" warnings have been issued around the country as Callum – the third named storm of the season – barrels up the UK coast from the Atlantic on Friday.

Yellow warnings had been issued for Northern Ireland, Wales and Western Scotland earlier this week.

But now a more serious Amber warning has been put in place for South Wales and parts of South West England.

The upgraded Met Office warning means that flooding caused by torrential rain and leaves blocking drains is more likely than first thought.

The yellow wind warning has also been extended to reach from the North of Scotland to the South of England, as powerful gales are expected from 3am on Friday morning.

Up to six inches of rain will fall on Northern and Western areas will fall at the same time before the deluge tracks westwards into Saturday and beyond.

The weather system – described by the Met Office in the Amber and Yellow warning as "intense" – will also bring with it strong gales that will see large swells in coastal areas.

For tomorrow, the Met Office said: "A zone of heavy rain associated with an intense weather system affecting western parts of the UK will become slow moving for a time".

This will bring "prolonged rainfall and the potential for surface water flooding", the weather warning added.

"Areas of high ground exposed to the south and south west will be most affected, with the potential for over 60mm of rain in 12 hours in the most exposed locations, and over 100mm by the end of the day."

What is an Amber weather warning?

There is an increased likelihood of bad or extreme weather, potentially disrupting plans and causing travel delays.

Road and rail closures, interruption to power and the potential risk to life and property are also considered probably in an Amber warning.

Be prepared to change your plans and protect you, your family and community from the impacts of the severe weather.

It is more serious than a Yellow warning which means "be aware" and less serious than a Red warning meaning "take action".

It added: "The rain is expected to be accompanied by strong winds, which when combined with high tides may lead to some coastal impacts due to large waves.

"In addition, these winds may increase autumnal leaf fall, which would increase the potential for blocked drains and culverts, heightening the flooding risk."

The wet and windy weather will continue well into the weekend for much of Scotland and Wales as weather warnings remain in place for Saturday.

Strong south-easterly winds will also add to the stormy feel — with a "medium" level of impact expected.

Some rural communities could even become cut off as the floods block smaller B-roads.

Met Office chief meteorologist Frank Saunders, said: “Strong winds at this time of year can increase the rate of leaf fall which can potentially block drains or culverts and, with the heavy rainfall expected over Friday and Saturday, could well heighten the potential for flooding.

"There is also a risk that the high winds associated with Storm Callum, combined with high tides, may lead to some coastal impacts due to large waves.”

The wet weather is set to come on the tail-end of Tropical Storm Leslie — which is currently helping sweep up warm air from the Canary Islands to Britain.

Despite the storms, temperatures have been much higher for this time of year than usually expected during Autumn.

The last time temperatures exceeded 24C at this time of year was in October 2011 when a staggering 29.9C was clocked.